This dissertation, "The Early Development of Children From Different Socioeconomic Backgrounds: Do Our Children Need Early Intervention?" by Patrick, Ip, 葉柏強, was obtained from The University of Hong Kong (Pokfulam, Hong Kong) and is being sold pursuant to Creative Commons: Attribution 3.0 Hong Kong License. The content of this dissertation has not been altered in any way. We have altered the formatting in order to facilitate the ease of printing and reading of the dissertation. All rights not granted by the above license are retained by the author. Abstract: BackgroundChild development is adversely affected by the socioeconomic status of the family and community. In view of the increasing socioeconomic disparity in Hong Kong in the past decade, this proposed study aims at investigating the existence, magnitude, pattern and manifestations of socioeconomic gradients in school readiness of preschool children, as well as interpreting how these are shaped and mediated through families, institutions and the wider communities. Objectives1) To adapt and validate the Chinese Early Development Instrument (CEDI);2) To investigate the socioeconomic gradients in school readiness of preschool children in relation to family SES, contextual effect, and family processes. MethodsThis study employs a cross-sectional research design comprising two stages. Stage one was a stand-alone pilot study to translate and validate the Chinese version of Early Development Instrument (CEDI). A total of 167 K3 children (4 kindergartens) from Hong Kong Island (HKI, the affluent district) and Yuen Long (YL, the disadvantaged district) were recruited. Stage two was the main study to examine socioeconomic gradients in school readiness. 567 K3 children of 21 kindergartens from YL and HKI were recruited. Four hypotheses regarding socio-economic gradients in terms of existence, magnitude, pattern, and mediating mechanism were tested using two-level linear models. ResultsCEDI showed adequate internal consistency, with Cronbach's alpha ranging from .70 to .95. The concurrent validity of CEDI was established using The Pearson correlations between CEDI and Hong Kong Early Child Development Scale (HKECDS), locally developed direct assessment, ranged from .39 to .66 with statistical significance (pIn the main study, children from YL have a significantly lower total CEDI domain score of emotional maturity (p= .025) and language and cognitive development (p= .01) than their counterparts from HKI. Girls scored significant higher on the total CEDI scores (mean= 44.5, sd= 4.80) than their male counterparts (mean=42.52, sd=6.10), and significantly less proportion of girls than boys were classified as developmentally vulnerable in at least one CEDI domains (26.0% girls vs. 35.8% boys, p=0.12). Hypothesis testing regarding existence of socioeconomic gradient by multi-level modeling suggested a significant association between the overall developmental outcomes of children and family SES index. Testing of kindergarten's contextual effect showed that kindergarten level variables (annual school fees, teacher education background and working experience) accounted for significant proportion of variance in the total CEDI score. Additionally, our results supported the mediating effect of family processes (i.e., frequency of parent-child interactions and management of child digital use at home) in explaining socioeconomic gradients in child developmental outcomes. ConclusionsCEDI is a psychometric sound measurement tool for early child development and assessing school readiness in Chinese society. Using CEDI, the evidence gathered from the main study demonstrated the existence of socioeconomic gradient with a significant association between the developmental outcom